Masonry lintels have been used throughout history and have withstood the test of time in many instances. Why is the masonry lintel such an efficient design compared to other available materials? You might think higher strength values can be achieved using other materials, however, masonry lintels built integral with the wall can produce robust and efficient designs in most cases.
In the April 2019 SE University session, Cathleen Jacinto presented Lintels for Masonry Walls. Cathleen reviewed the behavior and load distribution of lintels and masonry walls with openings and discussed practical design and detailing strategies to achieve high performing lintels. Cathleen also explained the advantages of analyzing masonry walls with finite element software.
As necessary elements within a masonry wall, lintels can be built integral with the wall, or be constructed using other materials. Cathleen reviewed the benefits of using masonry for lintel design as shown on the following slide:
Masonry lintels are typically more easily constructed since there is less coordination between disciplines and the masonry lintel ties in easily with the masonry jamb. Because of this fixity between the lintel and the jamb, a masonry lintel offers a more fixed-end condition than lintels using other materials which increases the strength of the overall wall.
Cathleen strongly recommended locating control joints away from the openings, so that arching action can be achieved. Perforated shear walls using masonry lintels can have three times the shear capacity compared to a masonry wall with control joints at the openings due to this increase in strength from arching action. With the option of prefabricated masonry lintels, longer spans are achievable making masonry lintels on par with other alternatives. Also, there is no concern for differential movement between the wall and lintel, as there may be with dissimilar materials, and there is less likely to be issues with thermal breaks.
Masonry lintels provide robust and heavy load resistance, which can enhance the performance of the masonry wall. Recent advances in shoring techniques and constructability make it an attractive option, even when shoring or prefabrication may be required. Removing some of the concerns about differential movement can add to the reasons why you may want to consider designing a masonry lintel with your next masonry wall.